Drill-bit-blade construction



Nov. 1, 1927.

' G. B. SIPE DRILL BIT BLADE CONSTRUCTION Filed Nov. 1923 Patented Nov. 1, 1927.

UNITED STATES PATENT OFFICE.

DRILL-BIT-IBLADE CONSTRUCTION.

Application filed November 8, 1923. Serial No. 673,584.

This invention relates to improvements in drills and underreamers.

The primary object of this invention is the provision of an improved bit and bit blade construction for drills and underreamers such as are shown in Patent No. 1,360,328, issued November th, 1920, to J. C. Stokes, and Patent N 0. 1,379,483, issued May 24, 1921, to J. o. Stokes.

A further object of this invention is the provision of an improved blade construction for bits embodyinga supporting portion and a removable cutting portion.

A further object of this invention is the provision of a bit construction for drills such as are used in connection with the drilling of shafts for caissons, such as set forth in my copending application Serial No. 671,015, filed October 26, 1923, and embodyin means by which the cutting portion of the %it may be made selectively wider or narrower without necessity of dismantling the entire bit construction; it being necessary at times to drill the bore of the shaft of greater or less diameter in accordance with the method of producing and placing piles as set forth in my copending application referred to.

A further "object of this invention is the provision of a collapsible bit construction which embodies blades having removable 1 cutting portions of novel construction.

Other objects and advantages of this invention will be apparentdurlng the course of the following detailed description.

In the accompanying drawing, forming a part of this specification, and wherein similar reference characters designate corresponding parts throughout the several views,

Figure 1 is a fragmentary view, partly in cross section, of a drilling stem, showing the manner in which the improved bit construction is used therein,

Fig.2 is an enlargedview of the bit construction substantially as is illustrated in Figure 1.

Fig. 3 is a bottom plan view of the blades of the improved bit construction.

Fig. 4 is an end elevation of the improved blades of the bit construction shown in their assembled cutting relation.

Fig. 5 is a cross sectional view taken substantially on the line 55 of Figure 1, and

Fig. 6 is a side elevation of a blade cuttin section which maybe used in lieu of one 0% the cuttin sections illustrated in Figures 1 and 2 of t e drawing.

' with respect to the plane defined by the front In the drawing, wherein for the purpose of illustration is shown but the preferred embodiment 'of this invention the letter A may generally designate the improved bit construction, which may be used in connection with a drilling stem B, either of the Well known type, or of the type shown in the patents above-referred to as issued to John C. Stokes. I

Referring to the bit construction A, the same preferably includes a bit carrier 0, and the blades D and E which are collapsibly supported thereby in accordance with the construction set forth in the patents of John C. Stokes above referred to.

Each of the blades D and E includes a supporting'orbody portion 10; and a cutter portion or construction 11. In the supporting portion. 10 thereof the blades D and E are provided with elongated slots 12, which receive therethrough a bolt construction 14 of the bit carrier 0; this bolt being of such nature that when the bit A is drawn upwardly into the stem B, carrier 0 may move relatively upward on the blades D and'E so that the bolt ridi'n in the slots 12 will draw the blades D and into a collapsed relation. so that they may pass upwardly througlrthe passageway 16 of the stem B, and as is more scpecifically set forth in the patents of John Stokes above referred to.

The blades D and E are of identical formation, and thesupporting portion 10 of each of the same is of substantially flat metal suitably formed on the upper portion thereof to cooperate with the bit carrier C and the construction'of the drill stem B in the man ner' desired. At its lower end each blade 10 is provided with a pocket or recess 12, which 95 extends inwardly from the front surface 13 of the supporting or body portion 10, the surface 14 of this pocket or recess 12 being disposed in a plane which is at an acute angle surface 13 of the supporting portion 10.

Referrin to the ,cutter portion 11, the same is of unique construction for each blade 10, and includes a plurality of blade cutter sections which are preferably each of the same height, although they may vary as to width. The cutter portion for each blade D preferably comprises the outer section 25; inner section 26; and intermediate sections 27. Each blade section includes an attaching portion 28 at the upper end thereof, and a lower cambered cutter part 29.

In the attaching portion 28 of'each cutter section a pair of apertures 30 are preferably provided, which are adapted to receive bolts '31 therethrough whereby the blade cutter section may be securely attached to the supporting portion in the recess or pocket 12 at the lower end thereof.

. In the assemblage of the cutter sections 25,

I 26 and 27 the same are arranged side by side, 10 and secured by means of the bolts 31 in the recess or pocket 12 of the'blade supporting portion 10, and so that the cambered sharpened portions .29 of the cutter sections extend below the lower edge of the blade support 10, in order to effectively perform the drilling or cutting operation. The attaching portions 28 of the cutter sections are of course arranged in the pockets, and in" this connection the top edges of said cutter sections engagethe top surface 35 of the pocket 12,

and the rear surfaces of the attaching portions 29 abut the rear surface 14 of the pocket 12. The bolts 31 are entirely secreted within the supporting and cutting portions 2 of the blades; it being preferred to provide countersunk openings in the fronts of the cutter sections to receive the heads of the bolts, and to provide countersunk openings inwardly of the rear surface of the'blade I 'support portion 10 to receive the nuts and rear ends of the shanks of the bolts, substantially after the construction illustrated in Figure 5 of the drawing. The cutter sections of the blades are cambered on different 35 pitches, but when in alignment to form the cutter portion 11 the cutter sections are in fiush'relation to provide an even front concaved surface and an even rear convexed surface, substantially as is illustrated in the 40 drawing. The cutter sections are each individually connected in a stable and secure relation to the supporting portion 10 of the blade, and may be individually removed without the necessity of detachment or removal of the other cutter sections.

\ x In the construction of bit blades it has heretofore been customary to form the blade as an integral unit. However, with the advent of the drill such as set forth in the patcuts of John C. Stokes above referred to, it

has become possible to drill wells, and sink shafts with bores which in soine instances exceed six feet in diameter. It is thus readily apparent that the bit blades are of huge size in many --instances, weighing considerable, and being expensive to manufacture. Such bit blades where made integral are a complete loss if the cutting edge thereof becomes chipped; and if it is desired to vary the diameter of the bore when drilling for caisson work, as where the bit encounters rock, and as is set forth in my copending application above referred to, it becomes necessary to change the blades so that the diameter of the bore may be varied. The

changing of these blades from the bit assemblage is a considerable problem. However, with the improved cutter construction l1it is merely necessary to change the out-- side cutter sections 25, as thereby the diameter of the bore may be varied at will.

In Figure 6 has been illustrated an outside blade 25 which shows that the cambered cutting part 29 thereof has a greater span than has the cutting parts 29 of the sections 25 illustrated in Figures 1 and 2 of the drawin. As is sometimes the case the wear on b the cutting edge at one portion of the blade is greater than the other, and the mere replacement of the section of the cutter portion which thus becomes dull as to its cutting edge, takes care of the entire blade, in contradistinction' to the replacement of the entire blade where a blade of integral construction is used.

' When the bladesv D and E are assembled in the bit arrangement A, thecutting ed es 40 and 41 of the cutter portions 11 0 said blades D and E respectively are arranged in true alignment, and in the bore of a shaft being sunk are arranged in true diametrical' relation with said bore. These cutting edges 40 and 41 in order to achieve this result are, A

of course, arranged on a line diagonally with respect to the plane formed by the supporting portions of said blades, and as is clearly illustrated in Figure 3 of the drawmg. I

From the foregoing description of this invention it is apparent that an improved blade and bit construction for drills and underreamers has been provided, which is of great importance from the standpointof simplification of operation, economy, and durability.

Various changes in the shape, size, and arrangement of parts may be made to the form of the invention herein shown and described, without departing fro thesp-irit of this invention or the scope oft e claims.

I claim:

1. As an article of manufacture a bit blade comprising a substantially flat supporting portion provided with an upwardly extending recess in the lower end thereof at an angle to the plane of the supporting portion, a plurality of cutting sections having the lower cutting ends thereof vertically cambered, and bolt means for each of said sections for connecting them in the recess of said supporting portion whereby the cambered cutting parts of said sections extend below the supporting portion and are arranged flush with each other toprovide a cutter construction for the blade.

2. In a drill bit, a hollow holder, a sup port collapsibly carried by said holder so as to from, and a plurality of detachable blade sections rigidly carried by said support in flush edge-engaging relation.

be retractible therein or extensible therelow drill stem, a carrier reciprocably mounted in the drill stem, a pair of blades collapse bly connected with said carrier by means of which the blades may be collapsed within the drill stem or extended therefrom into a cutting relation, said blades eachincluding a cutter portion which is cambered in a longitudinally concavo-convex relation with the camber varied in degree from the inner edge of the blade where the cambered degree is least to the outer edge of the blade where the cambered degree is greatest, each of said blades having a cutting edge for the cutter portion arranged transversely at an angle to the general plane of the respective blade in" such manner that the cutting edges of the blades are in alignment when the blades are extended for "use with respect to the drill stem.

4. In a rotary drill the combination of a drill stem, a carrier collapsibly carried in the drill stem for movementtherein, supports collapsibly carried by the carrier to entirely collapse in -the drill stem with the carrier, and a sectional blade construction carried h each of said supports at the lower en s thereof, the sectional blade construction for each support consisting of a plurality of longitudinallv cambered sections which are cambered at diiferent degrees, with the sec- 'tion of least camber being disposed at the inner edge of the blade construction and the camber of greatest degree at the outer edge of the blade construction, the sections of the blade construction being provided with cuttt-ing edges in aligning relation to provide a general cutting edge for each blade construction which is arranged transversely at an angle to the plane of the respective blade construction. Y

5. As an article of manufacture a bit blade comprising a flat S11 1) rting body and a sectional cutting porti n detachably connected in stable relation to the body, and comprisii'ng aplurality of sections each having a cutting edge, the sections being so arranged on the body that the cutting edges are in contiguous alignment extending transversely gtdan angle to the plane of the supporting 6. In a rotary drill the combination of a drill stem, a carrier, blades collapsibly supported by the carrier with respect'to the drill stem each of said blades including a body portion of one piece and a plurality of detachably connected concavo-convex cutter sections each of the same being arcuated on a different pitch, the sections for each blade when assembled on the body portion of the blades having their cutting edges in aligning relation arranged at an angle with respect to the plane of the blade.

7 A drill bit blade comprising a supporting portion, a cutter portion including a plurality of sections each concavo-convexly cambered at different degrees, and means connecting the sections to the supporting portion in edge contacting relation, with the concave surfaces all flush and facing to the front of the blade and all convex surfaces lation across the blade according to their degree of camber.

GEORGE B. SIPE. 

